Four single mothers today described their experiences of the “irrational” and “discriminatory” Universal Credit system in a landmark hearing at the High Court.

The women, who are all working single mothers, argue a “fundamental problem” with the controversial welfare scheme means their monthly payments vary “enormously” and they end up out of pocket.

The court heard on Tuesday they are struggling to manage their household budgets as a result and some have fallen into debt or had to rely on food banks.

Lawyers for the four said the problem is likely to affect “tens of thousands of people” claiming Universal Credit, which was introduced to replace means-tested benefits including income support and housing benefit.

Jenni Richards QC, representing the women, told the court: “The claimants in this case all have a number of things in common.

“They are all lone parents, they have all been doing their utmost to work and not depend solely on benefits.”

“There is no reason to suspect they are anomalous or isolated cases,” she added.

One of the women, Danielle Johnson, 25, from Keighley West Yorkshire, works part-time as a dinner lady and receives Universal Credit to top up her income.

She is challenging the government via judicial review along with three other women in a similar situation. 

As well as arguing that the Universal Credit payment system is irrational, she also said the system is discriminatory as it disproportionately affects single parents, who are predominantly female.

Johnson has said previously: “I have never been this financially unstable before, to the point of being unable to afford my rent and having to go into my overdraft when buying food.

“It is getting me into a vicious cycle of debt. Universal Credit is supposed to be simpler and fairer, but my experience of it is the opposite. I’m doing my best working part-time to make ends meet so that I can look after my daughter.

“I thought the government was supposed to help and support people like me trying to get back to work but I have found it to be the opposite.”

Lawyers said the problem arises when claimants are paid by employers on a date which “clashes” with their assessment period for Universal Credit.

For example, if a claimant is paid early because of a weekend or bank holiday, the system counts them as having been paid twice in one month and they receive a “vastly reduced” Universal Credit payment, the court heard.

Universal Credit has proven to be a highly controversial policy for the government, with delays to initial payments leaving some claimants relying on food banks and struggling to pay their bills. 

It was introduced to simplify the benefits system, rolling six types of payments under the old system into one.

A similar High Court case earlier this year found Universal Credit was unlawfully discriminating against severely disabled people. 

Last month, veteran MP Frank Field claimed the system was driving women in his constituency into sex work in a bid to avoid complete poverty.

Meanwhile, thousands more benefits claimants are set to be moved onto the Universal Credit system next year, despite warnings from charities.

A DWP spokesman said: “Universal Credit adjusts automatically to people’s earnings so if someone’s earnings are higher one month their Universal Credit payment decreases, but they may receive an increased Universal Credit amount the following month.

“People can see how much Universal Credit is due to be paid into their account online, and budget support is available to those who need it.”